The present invention relates to a process of purifying beet juice by means of ion exchangers.
The conventional manufacture of sugar from sugar beets is effected by means of a series of operations which include cutting the washed beets into slices; treating the slices with preheated water which dissolves the sugar and water-soluble material; purifying the resultant sugar juices by preliming and liming, which eliminate, by precipitation, the organic and inorganic materials which interfere with subsequent crystallization, carbonation, and filtration; which produces juices containing sugars and salts from which the sucrose is separated by the steps of concentration, crystallization, and centrifuging, leaving a residue, namely, molasses. However, this relatively lengthy process consumes substantial amounts of energy and gives, prior to the crystallization step, a sugar syrup which still contains impurities which, after the crystallization step, are present in the molasses into which they entrain a substantial part of the desired sucrose, thus decreasing the yields of sucrose.
It is known to treat sugar beet juices by means of ion-exchange resins after flocculation with alcohol in order to separate the different components for purposes of analysis. However, while these techniques make it possible to establish the composition of the juices, they are not helpful in producing crystallizable sugar syrups on an industrial scale.
The process of the invention makes it possible to avoid the conventional steps of liming, carbonation, and filtration and also makes it possible, by eliminating all the organic nitrogen materials, to obtain from the sugar beet juices a purified sugar syrup having a good yield of sucrose, by means of only a single operation, which consumes very little energy.
The foregoing, therefore, describes several among the important objects of the invention.
It is a further object of the present invention to provide a novel process for the purification of sugar beet juices, employing ion exchangers.